Parietal Bone Metastasis of Rectal Adenocarcinoma as an Initial Diagnosis of Recurrence: Case Report

Abstract

Colorectal cancer (CRC) is a most common and lethal disease of the gastrointestinal tract [1]. CRC can usually spread by lymphatic and hematogenous routes. The most common metastatic sites are the regional lymph nodes, liver, lungs, and peritoneum [1]. Uncommon metastasis of CRC were described such as skin, muscles, skull and thyroid [2][3][4][5][6]. Involvement of unusual sites with metastasis frequently occurs in the presence disseminated disease. Thus, the patient presented with widespread metastasis had poor prognosis [4]. Although all types of tumors lead to metastasis to skull hematogenous route, breast cancer and lung cancers are associated with the highest rate, skull metastases of CRC are quite rare [5]. Parietal bone metastasis without vertebral bone metastasis from CRC is an unexpected situation. The most common presenting symptom of skull metastases is a visible, localized swelling of skull produced by growing tumor [7]. Herein, we report a case of patient with a visible, localized swelling of skull.A 44-year old man had diagnosed with adenocarcinoma of the rectum as a result of colonoscopic biopsy in July 2009. Fluoropyrimidine-based neoadjuvant chemoradiotherapy had performed. "Low Anterior Resection" was held in September 2009 and after surgery 4 cycles adjuvant chemotherapy had admitted. The patient was followed in remission until February 2012. He had presented with a mass approximately 6 cm in diameter located his temporoparietal region in February 2012. The mass had grown rapidly in 4 or 5 months. Because of tumour diameter and pain, he had applied to Neurosurgery Department. Magnetic resonance imaging (MRI) showed a 6.0x4.0 cm mass, extending from bottom of scalp and epidural space (Figure 1). The mass had excised with parietal bone. After histopathological evaluation of parietal bone, the diagnosis was metastatic adenocarcinoma. Immunohistochemical analysis was positive for TTF-1, CK-19, CK-20 and CDX2. The specimens were negative for PSA, CK-7, CD10, surfactant. The final diagnosis was metastatic adenocarcinoma of CRC. He applied to Medical Oncology Department in April 2012. Palliative radiotherapy was performed to parietal bone. After the radiotherapy to the parietal bone, infusional 5-fluorouracil, leucovorin, and irinotecan and bevacizumab (FOLFIRI-BEV) was planned but he refused chemotherapy. He applied to Medical Oncology Department because of neurological complaints in July 2012. After re-staging new metastatic lesions detected in lungs, brain metastasis. Bone scan revealed widespread skeletal metastasis. Palliative radiotherapy was performed to painful bone lesions. Due to poor performance status no chemotherapy applied and he had followed up with best supportive. The patient died 9 months after the diagnosis of parietal bone metastasis. The most common metastatic sites of colorectal cancer are the regional lymph nodes, liver, lung, and peritoneum. Parietal bone metastasis without vertebral bone metastasis from colorectal cancer is an unexpected situation. Herein, we report an unusua...